[BACKPORT 4.14.y 6/8] power: supply: sysfs: ratelimit property read error message

From: Baolin Wang
Date: Tue Sep 03 2019 - 03:00:27 EST

From: David Lechner <david@xxxxxxxxxxxxxx>

This adds rate limiting to the message that is printed when reading a
power supply property via sysfs returns an error. This will prevent
userspace applications from unintentionally dDOSing the system by
continuously reading a property that returns an error.

Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
drivers/power/supply/power_supply_sysfs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index eb5dc74..2ccaf4f 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -91,7 +91,8 @@ static ssize_t power_supply_show_property(struct device *dev,
dev_dbg(dev, "driver has no data for `%s' property\n",
else if (ret != -ENODEV && ret != -EAGAIN)
- dev_err(dev, "driver failed to report `%s' property: %zd\n",
+ dev_err_ratelimited(dev,
+ "driver failed to report `%s' property: %zd\n",
attr->attr.name, ret);
return ret;